This technique is based on the process principles of xerographic printers, (for example, laser or LED printers) that combine electrostatic printing with photography.
In 1975, he obtained his PhD from the University of Rochester under Elliott Waters Montroll for a thesis entitled A Stochastic Theory of Anomalous Transient Photocurrents - in Certain Xerographic Films and of the 1/f Noise in Neural Membrane.